MDEV-408: SHOW EXPLAIN: Some values are chopped off in SHOW EXPLAIN output

- Fix I_S table definition for EXPLAIN output.

mysql-test/r/show_explain.result

@@ -926,4 +926,29 @@ a
 16
 set debug_dbug='';
 drop table t1;
+#
+# MDEV-408: SHOW EXPLAIN: Some values are chopped off in SHOW EXPLAIN output
+#
+CREATE TABLE t1 (a INT, b VARCHAR(35)) ENGINE=InnoDB;
+INSERT INTO t1 VALUES (3989,'Abilene'),(3873,'Akron');
+CREATE TABLE t2 (c INT, d VARCHAR(52) PRIMARY KEY, KEY(c)) ENGINE=InnoDB;
+INSERT INTO t2 VALUES (86,'English'),(87,'Russian');
+explain SELECT SUM(a + SLEEP(0.1)) FROM t1 WHERE a IN ( SELECT c FROM t2 WHERE d < b ) OR b < 's';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	DEPENDENT SUBQUERY	t2	index_subquery	PRIMARY,c	c	5	func	1	Using index; Using where
+set @show_explain_probe_select_id=1;
+set debug_dbug='d,show_explain_probe_join_exec_start';
+SELECT SUM(a + SLEEP(0.1)) FROM t1 WHERE a IN ( SELECT c FROM t2 WHERE d < b ) OR b < 's';
+show explain for $thr2;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	DEPENDENT SUBQUERY	t2	index_subquery	PRIMARY,c	c	5	func	1	Using index; Using where
+Warnings:
+Note	1003	SELECT SUM(a + SLEEP(0.1)) FROM t1 WHERE a IN ( SELECT c FROM t2 WHERE d < b ) OR b < 's'
+SUM(a + SLEEP(0.1))
+7862
+set debug_dbug='';
+drop table t1, t2;
+# End
 drop table t0;

mysql-test/t/show_explain.test

@@ -947,5 +947,32 @@ set debug_dbug='';
 
 drop table t1;
 
-drop table t0;
+--echo #
+--echo # MDEV-408: SHOW EXPLAIN: Some values are chopped off in SHOW EXPLAIN output
+--echo #
+CREATE TABLE t1 (a INT, b VARCHAR(35)) ENGINE=InnoDB;
+INSERT INTO t1 VALUES (3989,'Abilene'),(3873,'Akron');
+
+CREATE TABLE t2 (c INT, d VARCHAR(52) PRIMARY KEY, KEY(c)) ENGINE=InnoDB;
+INSERT INTO t2 VALUES (86,'English'),(87,'Russian');
+
+explain SELECT SUM(a + SLEEP(0.1)) FROM t1 WHERE a IN ( SELECT c FROM t2 WHERE d < b ) OR b < 's';
+
+set @show_explain_probe_select_id=1;
+set debug_dbug='d,show_explain_probe_join_exec_start';
+--send
+SELECT SUM(a + SLEEP(0.1)) FROM t1 WHERE a IN ( SELECT c FROM t2 WHERE d < b ) OR b < 's';
+
+connection default;
+--source include/wait_condition.inc
+evalp show explain for $thr2;
+
+connection con1;
+reap;
+
+set debug_dbug='';
 
+drop table t1, t2;
+
+--echo # End
+drop table t0;

sql/sql_show.cc

@@ -8495,11 +8495,11 @@ ST_FIELD_INFO show_explain_fields_info[]=
     SKIP_OPEN_TABLE},
   {"table", NAME_CHAR_LEN, MYSQL_TYPE_STRING, 0 /*value*/, MY_I_S_MAYBE_NULL,
    "table", SKIP_OPEN_TABLE},
-  {"type", 11, MYSQL_TYPE_STRING, 0, MY_I_S_MAYBE_NULL, "type", SKIP_OPEN_TABLE},
+  {"type", 15, MYSQL_TYPE_STRING, 0, MY_I_S_MAYBE_NULL, "type", SKIP_OPEN_TABLE},
   {"possible_keys", NAME_CHAR_LEN*MAX_KEY, MYSQL_TYPE_STRING, 0/*value*/,
     MY_I_S_MAYBE_NULL, "possible_keys", SKIP_OPEN_TABLE},
-  {"key", NAME_CHAR_LEN, MYSQL_TYPE_STRING, 0/*value*/, MY_I_S_MAYBE_NULL, 
-   "key", SKIP_OPEN_TABLE},
+  {"key", NAME_CHAR_LEN*MAX_KEY, MYSQL_TYPE_STRING, 0/*value*/, 
+    MY_I_S_MAYBE_NULL, "key", SKIP_OPEN_TABLE},
   {"key_len", NAME_CHAR_LEN*MAX_KEY, MYSQL_TYPE_STRING, 0/*value*/, 
     MY_I_S_MAYBE_NULL, "key_len", SKIP_OPEN_TABLE},
   {"ref", NAME_CHAR_LEN*MAX_REF_PARTS, MYSQL_TYPE_STRING, 0/*value*/,